The Taylor expansion we use in the analytical approximation of the regulariser results in the use of the Jacobian
of the model. Regularisers that use the Jacobian have previously been successfully used to control the stability/robustness
of models to noisy inputs. Relevant work includes contractive auto encoders, [1]},
and [2]}. [1]} use the Frobenius of the Jacobian at the input instances
to force the model to be relatively constant in small neighbors around the input instances. Such a
regulariser introduces invariance to small input variations. In a different setting [4]}, [4]},
used the Jacobian to learn sparse non-linear models in the context of kernels.
